As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FAULT AFTER SUCCESSFUL START UPON LANDING. T/S APU START NO FAULTS, T/S APU ECU BITE CODES 34 & 23 DISPLAYS SHUT DOWN 2 & 3 STARTS ABORTED FROM "A/C STRT CIRCUIT" LRU. SUMMARY CALLS OUT "ECS CTRL" & "A/C STRT CIRUIT" 1529 UTC PERFORMED FIM 49-11 FT 987. NO FAULTS NOTED AT THIS TIME. APU OPS CHECK GOOD.